Atomic layer deposition has been developed as a technique which can uniformly form a very thin film with an excellent step coverage (see patent reference 1: Japanese Patent Laid-Open No. 1-179423 and patent reference 2: Japanese Patent Laid-Open No. 5-160152). The atomic layer deposition is a technique of forming a thin film by depositing atomic layers one after another by alternately supplying materials of respective elements constituting a film to be formed. In the atomic layer deposition, one or n layers alone are adsorbed onto the substrate surface while supplying the materials of the respective elements so that no surplus materials contribute to the deposition. This is called the self-limiting deposition.
The atomic layer deposition has both a shape adaptability and film thickness controllability as high as those of the general CVD (Chemical Vapor Deposition), and is therefore expected to be practically applied to the formation of a capacitor and an insulating film called the “high-k gate” of a memory device. Still better, the atomic layer deposition can form an insulating film at temperatures as low as about 300° C., and is therefore expected to be applied to the formation of, especially, the gate insulating film of a thin-film transistor of a display device using a glass substrate.